Format

Send to

Choose Destination
J Bacteriol. 1995 Apr;177(7):1840-3.

The Alcaligenes eutrophus protein HoxN mediates nickel transport in Escherichia coli.

Author information

1
Institute für Biologie, Humboldt-Universität zu Berlin, Germany.

Abstract

HoxN, an integral membrane protein with seven transmembrane helices and a molecular mass of 33.1 kDa, is involved in high-affinity nickel transport in Alcaligenes eutrophus H16. From genetic analyses, it has been concluded that HoxN is a single-component ion carrier. To investigate this assumption, hoxN was introduced into Escherichia coli. The recombinant strain showed significantly enhanced nickel uptake in a short-interval assay. Likewise, growth in the presence of 63NiCl2 yielded a more than 15-fold-increased cellular nickel content. The HoxN-based nickel transport activity could also be demonstrated in a physiological assay: an E. coli strain coexpressing hoxN and the urease operon of Klebsiella aerogenes exhibited urease activity 10-fold greater than that in the strain lacking a functional hoxN. These results strongly suggest that HoxN is sufficient to operate as a nickel permease. Multiple sequence alignment of HoxN and four other bacterial membrane proteins implicated in nickel metabolism revealed two conserved signatures which may play a role in the nickel translocation process.

PMID:
7896709
PMCID:
PMC176814
DOI:
10.1128/jb.177.7.1840-1843.1995
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center